Refrigeration apparatus



Jan. 9, 1940. F. R. ERBACH 2,186,782

REFRIGERATION APPARATUS Filed Aug. 27, 1930 2 Sheets-Sheen 1 1e 5% .U INVENTOR.

Fame/0:2. EEBHCH Patented Jan. 9, 1940 UNITED STATES REFRIGERATIONAPPARATUS Frederick R. Erbach, Detroit, Mich., assignor, by

mesne assignments, to Nash-Kelvinator Corporation, Maryland Detroit,Mich.,

a corporation of Application August 27, 1930, Serial No. 478,172

16 Claims.

This invention relates to refrigerating apparatus employed for liquidcooler purposes and more particularly relates to automatic suction cutoif valves for employment in such mecha- A nism. I

The object of this invention is to provide a suction cut off valve to beused with a flooded refrigerant evaporator which will automaticallyclose the suction lines associated with the evap- W orator when theinterior of the evaporator reaches a predetermined low temperature.

Difficulty has been experienced heretofore in cooling liquids to acomparatively low temperature without occasionally freezing the liquidwith m resulting damage to the refrigerating apparatus.

This occasional freezing-up has been found to take place due toa settingof the control switch for operation of the system at low temperatureswhen there are numerous demands for drinking 20 water at comparativelyshort intervals, such, for example, as in schools, oifices or steelmills and the like. In practice, it has been found that the controlswitch may be set to operate the system so that the refrigerant in theevaporator 26 is at a temperature about or below freezing when there arenumerous demands at short intervals without the possibility of freezingthe water to be cooled owing to the heat of the incoming water whichprevents such freezing. Under such 30 conditions, the switch is likelyto be purposely set too low or misadjusted when attempting to take careof the peak demands. However, in schools, oflices or steel mills whichoperate but five or six days a week, it has been found that over theweak-ends or holidays when there is no demand for water, the systemcycles by heat leakage through the insulation into the cooler whichwarms up the system sufficiently to start the compressor operating. Inthe event the 40 switch is misadjusted and no incoming warm water is hadthe temperature of the refrigerant in a flooded evaporator is at anabnormal or undesired low value which during the on-phase of therefrigerating cycle causes some ice to be frozen on the outer wall ofthe evaporator. Also, when the switch is set to operate the system belowfreezing during such demands, the system will operate at undesired lowtemperatures when there is no demand for drinking water. During ,0 theoff-phase of the refrigerating cycle, with such switch setting, it hasbeen found that all of the ice does not melt, thus resulting in some ofthe ice remaining on the outer wall of the. evaporator. Under theseconditions, there is a cumulative freezing on the outer surface of thetake care of the peak demands and over a week- 5 end or a holiday, theswitch sticks or becomes otherwise faulty in operation, the temperatureof the refrigerant in the evaporator would fall to an abnormal lowvalue, resulting in freezing-up of the system. In addition, the switchmay be set 1 to operate the system so that the refrigerant in theevaporator is below freezing during a peak demand, and if the switchshould become faulty in operation, the temperature of the refrigerantmay reach an abnormally low value which is sufl5 flciently low enough tocause a freeze-up of the cooler even though there are numerous demandsfor drinking water at short intervals. Thus, it is an inherentcharacteristic of a water cooler, for different reasons, to freeze upoccasionally when 20 attempting to cool large quantities of water to thedesired temperature, unless some provisions are made to prevent suchconditions.

This invention provides a suction out off valve which, when used with arefrigerating apparatus 25 employing a flooded evaporator and a low sidepressure controller, will automatically lower the pressure in thesuction line to such an extent as to cause the pressure controller toshut off the refrigerant compressor before the liquid which is beingcooled is frozen.

In the drawings:

Figure I is a vertical cross sectional view of a flooded refrigerantevaporator showing a suction cut off valve embodying this invention inan a opening therein communicating with the suction line.

Figure II is an end view in elevation of the evaporator shown in FigureI.

Figure III is an enlarged side elevational view at of a suction cut offvalve embodying this invention.

Figure IV is across sectional view of the suction cut ofi valve shown inFigure III.

The suction out off valve embodying this inven- 45 tion isemployed inthe present instance with a refrigerant evaporator l3 consisting of twocylindrical shells l4 and I5 one disposed within the other in spacedrelation thereto, and having their adjacent ends sealed together as at8. The 50 inner shell I4 is spirally corrugated forming a circulatorypassageway between it and the outer shell I5 through which the liquid tobe cooled is circulated.

Liquid enters this passageway through an opena ing I6 and is withdrawnthrough an opening IT. The openings l6 and H are threaded to receivesimilarly threaded conduits. The inner shell is provided with a sealedclosure 1 at one end and at the other with an annular shoulder member 6secured in fluid tight contact therewith and carrying threaded openingsto receive bolts 5 which secure a head I2 in position.

Liquid refrigerant from a refrigerant compressor condenser structure byconduit 4| is admitted to the evaporator through an opening l8 in thehead l2. Its admission is controlled by a needle valve l9 which isoperated by a float 20 carried on one end of a bell crank lever 2| towhich the needle valve is pivotally connected and which is itselfpivotally connected to the extremity of an interiorally projecting arm 9carried on the interior surface of the head 12.

A suction cut off valve III is threaded into one side of an opening I lin the head l2, to the other side of which is connected a suction line42 leading to the refrigerant compressor condenser structure 40. Thesuction cut off valve II] is provided with a port 22 which is in opencommunication with the suction line 42 when the valve is in an openposition. Evaporated refrigerant fluiid when withdrawn from theevaporator I3 passes through the port 22 in the suction cut off valve l0into the opening II and through the suction line associated therewith tothe compressor 44.

The suction cut off valve I0 consists of cylindrical shell 23constructed of highly conductive metal, having a port 22 formed thereinand provided with a shoulder 24 having surfaces adapted to be engaged bya tool for revolving the shell. Beyond the shoulder 24 the shell 23 isprovided with a reduced portion 25 threaded for engagement with similarthreads on the inner side of the opening II in the evaporator l3. Anopening 26 through the reduced portion 25 leading into theinterior ofthe shell 23 is provided at its inner extremity with a valve seat 21adapted to receive a valve 28. A valve stem 29 carried by the valve 28is rigidly secured to a closure 36 for one end of an expansible bellows30. The opposite end of the bellows is provided with a closure 31 havingan opening 3| therein which also forms a closure for an opening 38 inthe shell 23. The interior surface of the closure 31 is made concave asat 33.

A short length of pliable tubing 32 is fitted into the opening 3! andsecured in fluid tight contact therewith. A liquid having an ascertainedfreezing point and cubical expansion upon freezing is introduced intothe bellows 30 through the tubing 32 filling the bellows completely. Theconvex surfaces 33 of closure 31 make possible the expulsion of all airwhen the bellows 30 is filled with liquid. After the bellows has beenfilled with liquid, the tubing 32 is pinched off as at 34 sealing theliquid within the bellows. With the bellows full of liquid the valve 28assumes the position shown in Figure IV. When the contents of thebellows freezes and expands, the valve 28 engages the valve seat 21.

A spiral spring 35 is positioned between the bellows closure member 36and the interior wall of the shell 23 adjacent to the valve seat 2'! tocollapse the bellows 30 when its contents are in a liquid state andcause the valve 28 to be withdrawn from its seat 21.-

It will be apparent that when the suction out off valve I0 is installedin an evaporator l3, as above described, and the evaporated refrigerantfluid surrounding the shell 23 and passing therethrough is at atemperature which will freeze the,

contents of the bellows 30, the valve 28 will close the opening 26 andreduce the pressure in the suction line leading to the low side of arefrigerant compressor condenser structure 40 and cause a low sidepressure controller 48 associated therewith to throw a switch cuttingoff the power which operates the compressor. It will also be apparentthat when the temperature of the gaseous refrigerant surrounding theshell 23 rises enough to melt the contents of the bellows 30, the spring35 will collapse the bellows and cause the valve 28 to be withdrawn fromits seat permitting the flow of refrigerant through the opening 26 intothe suction line. The bellows 30 may be filled with any liquid having afreezing point the same as or higher than that of the liquid to becooled by the evaporator. Heat will be transferred from the contents ofthe bellows to the refrigerant within the evaporator l3 at a more rapidrate than from the liquid in the passageway between the shells l4 and I5due to the excellent conductivity of the shell 23 and the fact that therefrigerant within the evaporator completely surrounds the shell 23 andthe bellows 30. It is therefore possible to use a liquid within thebellows having the same freezing point as the liquid to be cooled, asthe contents of the bellows 30 will become solidified and cause therefrigerant compressor 44 to shut off through the closing of the valve28 before the liquid circulating between the shells and I5 is frozen.

It will be apparent to those skilled in the art that the structuredisclosed herein is merely illustrative of the invention and that manymodifications and changes may be made in such structure withoutdeparting from the spirit of the invention or from the scope of theappended claims.

I claim:

1. In a refrigerating system of the flooded type, the combination withan evaporator of a. suction cut-01f valve disposed within saidevaporator, and means responsive to abnormally low temperature changesin the evaporator for closing said valve.

2. A valve structure comprising an expansible bellows containing afreezable liquid sealed therein, a shell of highly conductive materialsurrounding the bellows, a refrigerant inlet port and outlet port insaid shell, the movement of said bellows being primarily influenced bychanges in temperature of said shell, and means operatively associatedwith the bellows for closing the outlet port.

3. A valve structure comprising a cylindrical shell having a valve portin one end and a refrigerant inlet port in one side, a bellows sealedwith a freezable liquid disposed within said shell, a valve and valvestem operatively associated with said bellows for closing said valveport.

4. A valve structure, comprising: an expansible bellows containing afreezable liquid sealed therein, a shell of highly conductive materialsurrounding the bellows, a refrigerant inlet port and outlet port insaid shell, the movement of said bellows being influenced by changes intemperature of said shell together with changes in temoutlet port whenthe liquid in the bellows changes to a liquid state.

5. In a refrigerating system, the combination with an evaporator havinga refrigerant outlet port, and expansible means within the evaporatorand containing a freezable fluid arranged for' entirely closing saidport when said fluid is in a frozencondition and for entirely openingsaid port when said fluid is in an unfrozen condition.

6. In a refrigerating system, the combination with an evaporator havinga refrigerant outlet port, a valve member co-operating with said port,and means. within said evaporator responsive to a predetermined lowtemperature for causing said valve to entirely close said port, saidvalve remaining in a stationary position until said evaporator attainssaid predetermined low temperature.

'1. In a refrigerating system, the combination with an evaporator havinga header adapted to contain a quantity of liquid refrigerant, of meansproviding an outlet port in said header, and means in said headerresponsive only to abnormally low changes in temperature of therefrilgterant in the header for controlling said outlet p 8. In arefrigerating system, the combination with an evaporator having a headeradapted to contain a quantity of liquid refrigerant, of means providingan outlet port in said header, and means in said header including anexpansible element containing a freezable fluid in said headerresponsive to changes in temperature of the refrigerant in said headerfor opening and closing said outlet port.

9. In a refrigerating system, the combination with an evaporator of theflooded type having a header adapted to contain a quantity of liquidrefrigerant, said header having an inlet port for the admission ofliquid refrigerant and an outlet port for vaporized refrigerant, aridmeans within said header responsive to abnormally low changes oftemperature therein for closing said outlet port.

10. A water cooler comprising a flooded evaporator, means conductingwater to be cooled in thermal contact with the refrigerant in saidevaporator; means to prevent freezing the water in said means comprisinga thermostat controlled valve in the outlet for refrigerant gas fromsaid evaporator, said valve including an expansible element containing afreezing fluid in the evaporator responsive to changes in temperature insaid evaporator.

11. Refrigerating apparatus comprising an evaporator of the floodedtype, a refrigerant condensing element associated with said evaporator,means for controlling the operation of said condensing element inresponse to changes in temperatures in said evaporator for normallymaintaining a desired temperature, and additional control apparatusincluding an element in intimate metallic contact with the refrigerantin the evaporator and being arranged to modify the operation of saidfirst named control means in the event the temperature in the evaporatorreaches an abnormally low value to render the condensing elementinoperative.

12. In a refrigerating system, in combination, an evaporator, means forsupplying refrigerant to said evaporator, a suction line leading fromsaid evaporator, a valve in said suction-line for controlling the flowof refrigerant therethrough,

and thermally responsive means actuated by a freezing solution containedtherein for closing said. valve at a predetermined low temperature insaid suction line.

13. In a refrigerating system, in combination, an evaporator, means forsupplying refrigerant to said evaporator, a suction passage leading fromsaid evaporator, a valve in said passage for controlling the flow ofrefrigerant therethrough, and an element in said passage containing afreezing solution for closing said valve when the temperature in saidpassage is maintained at or below a predetermined low value for anappreciable length of time.

14. In a refrigerating system, in combination, an evaporator, means forsupplying refrigerant to said evaporator, a suction line leading fromsaid evaporator, a valve in said suction line, and expansible andcontractible means in said suction line and actuated by a freezingsolution contained therein for moving said valve to control the flow ofrefrigerant through said line.

15. In a refrigerating system, in combination, an evaporator, means forsupplying refrigerant to said evaporator including a compressor, asuction line leading from said evaporator, pressure actuated meansconnected with said suction line for controlling the operation of saidcompressor,- a valve in said suction line between said pressure actuatedmeans and said evaporator, and a delayed action temperature actuatedmeans in said suction line for controlling said valve, the lastmentioned means comprising an expansible member enclosing a normallyliquid material adapted to freeze and to expand after the extractiontherefrom of the sensible heat contained therein to close said valve.

16. In a refrigerating system, in combination, an evaporator, means forsupplying refrigerant to said evaporator, a suction line leading fromsaid evaporator, a valve in said suction line for controlling the flowof refrigerant therethrough, and freezable liquid in the suction linefor operating the valve, whereby said valve is affected by said liquidonly after the absorption therefrom of the sensible heat containedtherein.

FREDERICK R. ERBACH.

